1. Field of the Invention
The present invention relates to network enabled telephony devices, for example Voice over IP Telephones, configured for display applications remotely executable by a call server.
2. Description of the Related Art
Telephony devices have advanced to provide enhanced features for business consumers. For example, a business premises deploying a Private Branch Exchange (PBX) for intraoffice or interoffice communications utilizes telephony devices capable of receiving messages from the PBX, including a time of day string or a calling party identity string. However, proprietary PBX systems limit the availability of features that can be added to the telephony device. In addition, proprietary PBX systems typically provide voice-only services, such that text, data, or images cannot be transferred to the telephony device.
Voice over IP (VoIP) technology has evolved to provide network enabled telephony devices, for example Voice over IP telephony devices, configured for performing multiple operations that emulate a telephony device. VoIP telephony devices often include large display screens or other display capabilities, enabling new service features to be provided for a user. For example, the VoIP telephones, such as the commercially-available Cisco Telecaster 7960 IP Telephone from Cisco Systems, San Jose, Calif., includes user input and display operations. These user input and display operations enable a user to access multiple windows displaying respective applications based on soft key or hard key inputs, such as accessing a central telephone directory for retrieval of an employee's telephone number using a search query or selection from the displayed list. A user of the VoIP telephone can access one window configured displaying call status (e.g., duration of call, called party identity), or access another window configured for displaying the central telephone directory.
The executable software resident in the VoIP telephone, however, tends to be device-specific. Hence, the executable software needs to be rewritten for newer VoIP telephones having different hardware configurations (e.g., different sets of hard buttons, color display vs. greyscale display, different-sized display, etc.), although compatability issues may be reduced using hardware abstraction layers and input abstraction layers between the telephone display controller, the display portion, and the input portion. Moreover, the device-specific nature of the VoIP telephone software limits the manner in which different application services can be added to the VoIP telephone device for the device user: the VoIP telephone software needs to be modified to add the different application services. In addition, the VoIP telephone typically is configured for communication with a single call server, resulting in additional resource requirements imposed on the call server as services are added.
Browser-based telephony device technology is being implemented in wireless telephones using Wireless Application Protocol (WAP). In particular, WAP uses Extensible Markup Language (XML) technology to communicate interface changes to wireless devices such as digital wireless telephones and pagers, enabling applications and services to be provided to the digital wireless telephones. The use of XML tags enables the data to be displayed on the digital wireless telephone display in a prescribed manner.
The WAP-based approach to displaying data on the digital wireless telephone still suffers from the disadvantage that the input and display controllers of the digital wireless telephone interact with a single WAP portal (i.e., server), limiting the flexibility of the telephony device operations. In particular, a user is unable to send or receive a wireless telephone call on his or her web-enabled digital wireless telephone while using the digital wireless telephone to access the Internet.
Hence, the WAP-based systems still limit flexibility in delivering user interface applications to a telephony user.